Mountune Fiesta MRX Turbo

[re-rx7]

So a x47 on e30 and the mrx on 93 are probably pretty similar peak power wise? Will be interesting to see if someone runs aux fuel and ethanol blend with the mrx.

e30 TO e30 THEY ARE EVEN IMO.

 

[jeff]

e30 TO e30 THEY ARE EVEN IMO.

So after reading your reviews of your MRX I still can't tell whether or not you are happy. Could you give us a comparison of the C39 and MRX, highlighting what you like about each?

 

[re-rx7]

So after reading your reviews of your MRX I still can't tell whether or not you are happy. Could you give us a comparison of the C39 and MRX, highlighting what you like about each?

After owning a C39 i was getting about 30-31 lb min. Granted this was on a 55 degree day. Fast forward to few days ago and im moving 27lb a min on a mrx. Sae corrected, the Vdyno is exact. The MRX makes more tq in the middle 10-20lb ft but falls off after the turbo starts to lose boost. Which is interesting to me because the C39 never lost boost. It held all the way to redline 27psi or so, the only reason we stopped was because i was out of fuel. I havent ran out of fuel with the MRX. Draw your own conclusions. This doesn't make the MRX inferior. Just a diff powerband. I still believe the WG is the problem.
Looking back on some old threads the 2554R is rated at 27lb a min which is where Im at. Makes sense. The 11 blade compressor isnt meant for flow. Ill just leave it at that. I will be selling my MRX soon. It just was enough for what I was shooting for, not a bad turbo but not where i want my power levels.

 

[MitchsFiesta]

After owning a C39 i was getting about 30-31 lb min. Granted this was on a 55 degree day. Fast forward to few days ago and im moving 27lb a min on a mrx when its 85 degrees. Sae corrected the Vdyno is exactly the same till about 6k. The MRX makes more tq in the middle 10-20lb ft but falls off after the turbo start lose boost. Which is interesting because the C39 never lost boost. It held all the way to redline 27psi or so, the only reason we stopped was because i was out of fuel. I havent ran out of fuel with the MRX. Draw your own conclusions. This doesn't make the MRX inferior. Just a diff powerband. I still believe the WG is the problem. Looking back on some old threads the 2554R is rated at 27lb a min which is where Im at. Makes sense. The 11 blade compressor isnt meant for flow. Ill just leave it at that. I will be selling my MRX soon. It just was enough for what I was shooting for, not a bad turbo but not where i want my power levels.

For Ref..
The BW KP39 OEM turbo is capable of approx 21 lb/min

The GT2554R is capable of approx 27 lb/min
54mm compressor, 53mm turbine

The GT2560R is capable of approx 35 lb/min
60mm compressor, 53mm turbine

The GTX2860R is capable of approx 42 lb/min
60mm compressor, 53.9mm turbine

To be fair the MRX is pretty much a GTX2554r. Going by the 3582, going to the billet wheel yields about 10% more flow putting the mrx at about 30lb/min approx.

the one that I installed is having a similar issue where its loosing boost up top. Could be a wastegate issue though.

 

[re-rx7]

To be fair the MRX is pretty much a GTX2554r. Going by the 3582, going to the billet wheel yields about 10% more flow putting the mrx at about 30lb/min approx.

the one that I installed is having a similar issue where its loosing boost up top. Could be a wastegate issue though.

Absolutely could be a WG issue. Still 30lbs isnt gna make 300. Especially on pump since you will have to push it very very hard.

 

[letitreign]

Any Guestimate on what kinda whp that translates to?

A good estimate is your (lbs/min value x 10) - 10 = approx whp

 

[re-rx7]

Flywheel. According to Garrett. so figure 8-9whp. That's maxed out which usually means no pump

 

[eglove]

I got that advice from Tyler at Mountune btw, hes got some good pictures of the hose routing too. Another piece of advice, hook up all the turbo vacuum lines BEFORE installing it. Having to hook up the wastegate line post-turbo install was brutal. Routing the lines from the wastegate and intake elbow can be tricky too, watch out for hot things and the axle.

Yea I figured that out the hard way too, haha. Where did you route the harness? I still haven't figured out where I want it to go since it has that dead OEM BPV connector on it.

 

[re-rx7]

Wastegate looks awfully familiar. As stated I believe a 14psi or 22psi WG could do wonders on this turbo. However, I wish they would have done a 2560 instead of a 54. Another 8lb min there with no lag increase. Ill never understand.


https://www.turbobygarrett.com/turbobygarrett/turbochargers/gt2560r

 

[STAZ15]

Wastegate looks awfully familiar. As stated I believe a 14psi or 22psi WG could do wonders on this turbo. However, I wish they would have done a 2560 instead of a 54. Another 8lb min there with no lag increase. Ill never understand.


https://www.turbobygarrett.com/turbobygarrett/turbochargers/gt2560r

I see the same thing on my 2554 I'll peak at 23 psi and then drop to a little over 19 on the top end. The previous owner swap gas claims there is a 22psi wastegate on it. Ryan seems to disagree he thinks more like 14.


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[re-rx7]

Makeno mistake the MRX isn't a 2554 regular. It will hold 21 psi or so to redline and it flows a tad more.

 

[STAZ15]

Makeno mistake the MRX isn't a 2554 regular. It will hold 21 psi or so to redline and it flows a tad more.

This is the reason why I have been watching this thread I'm trying to decide if I want to go this route or maybe wait for what Vargas is going to offer.


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[FiestaTexas]

Yeah mine is getting to right under 28 lbs/min and holds a little over 22 psi at the limiter.

 

[BronxBomber]

After owning a C39 i was getting about 30-31 lb min. Granted this was on a 55 degree day. Fast forward to few days ago and im moving 27lb a min on a mrx. Sae corrected, the Vdyno is exact. The MRX makes more tq in the middle 10-20lb ft but falls off after the turbo starts to lose boost. Which is interesting to me because the C39 never lost boost. It held all the way to redline 27psi or so, the only reason we stopped was because i was out of fuel. I havent ran out of fuel with the MRX. Draw your own conclusions. This doesn't make the MRX inferior. Just a diff powerband. I still believe the WG is the problem.
Looking back on some old threads the 2554R is rated at 27lb a min which is where Im at. Makes sense. The 11 blade compressor isnt meant for flow. Ill just leave it at that. I will be selling my MRX soon. It just was enough for what I was shooting for, not a bad turbo but not where i want my power levels.

So Brandon, what numbers are you putting up on he MRX in comparison to your C39 and did PD tuning tune both or did Randy tune your MRX? Also, does it feel laggier compared to the C39? I was thinking about swapping my C39 out and going this route, but after hearing you less than thrilled, gotta say I may pass.

 

[re-rx7]

So Brandon, what numbers are you putting up on he MRX in comparison to your C39 and did PD tuning tune both or did Randy tune your MRX? Also, does it feel laggier compared to the C39? I was thinking about swapping my C39 out and going this route, but after hearing you less than thrilled, gotta say I may pass.

Both tuned by PD. Nothing against randy I just wanted consistency between the turbos. Not so much laggier the tq is apparent in the mid range. Honestly they feel about the same. I will say and have said multiple times that the wg may not be strong enough. As far as plots they are identical. It does make more mid tq at about 4300-5500

 

[Brura22]

Since y'all wanted hard proof.
300 whp confirmed. On a dynojet. Here's your airflow you asked for.

Love this turbo.
300 whp on pump without any extra e30 or meth.
Graphs speak for themselves.

 

[re-rx7]

Since y'all wanted hard proof.
300 whp confirmed. On a dynojet. Here's your airflow you asked for.

Love this turbo.
300 whp on pump without any extra e30 or meth.
Graphs speak for themselves.

31lb a min you say. Lol gtfo on pump. Can you read compressor maps? Send me a datazap of a log. 31lb a min at 25psi

 

[Brura22]

31lb a min you say. Lol gtfo on pump. Can you read compressor maps? Send me a datazap of a log. 31lb a min at 25psi

Man I'm not sure what you want. I guess I'm living in a fantasy land and didn't go to a dynojet and hit 300 on pump.
You're selling yours so oh well


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[re-rx7]

Man I'm not sure what you want. I guess I'm living in a fantasy land and didn't go to a dynojet and hit 300 on pump.
You're selling yours so oh well


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Here's what I'm saying. Other tuners are not seeing the same numbers you are, with 93, e30 ect. These are big name tuners. So unless randy has a magic wand up his ass.....see where I'm going. Also the previous graph you posted showed boost dropping to 19-20psi. This one shows it holding to 25?

 

[Brura22]

Here's what I'm saying. Other tuners are not seeing the same numbers you are, with 93, e30 ect. These are big name tuners. So unless randy has a magic wand up his ass.....see where I'm going. Also the previous graph you posted showed boost dropping to 19-20psi. This one shows it holding to 25?

Oh sorry I didn't know I couldnt proceed with revisions and tuning without letting you know.
Ever heard of WG preload?

No im not seeing where you're going. Are you tuning at sea level?
Sorry you aren't getting good results with your turbo.
I'm however loving mine and the numbers it put down on the rollers.
Happy boosting mate [emoji8]


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